1. Technical Field
The present disclosure relates to an optical imaging lens system. More particularly, the present disclosure relates to a compact optical imaging lens system applicable to a mobile terminal.
2. Description of Related Art
In recent years, with the popularity of mobile terminals having camera functionalities, the demand of miniaturized optical systems has been increasing. The sensor of a conventional optical system is typically a CCD (Charge-Coupled Device) or a CMOS (Complementary Metal-Oxide-Semiconductor) sensor. As the advanced semiconductor manufacturing technologies have allowed the pixel size of sensors to be reduced and compact optical systems have gradually evolved toward the field of higher megapixels, there is an increasing demand for compact optical systems featuring better image quality.
A conventional optical system employed in a portable electronic product mainly adopts a four-element lens structure or a five-element lens structure. Due to the popularity of mobile terminals with high-end specifications, such as smart phones, tablet personal computers and wearable apparatus, the requirements for high resolution and image quality of present compact optical systems increase significantly. However, the conventional optical systems cannot satisfy these requirements of the compact optical systems.
Other conventional compact optical systems with six-element lens structure enhance image quality and resolution. However, the surface shape and refractive power of the fifth lens element is not favorable for enlarging the field of view. Moreover, the refractive power of the second lens element and the third lens element cannot avoid the astigmatism and distortion from being excessively increased in a peripheral region of an image. Accordingly, it is not applicable to the mobile terminals with high image quality.